Modern cargo aircraft usually include integral loading ramps. The ramp usually forms a portion of the aircraft fuselage. Therefore, the end of the ramp is so thick that it is not feasible to drive vehicles on or off the ramp from the ground without the use of one or more auxiliary devices called ramp toes. The ramp toes are used to form a bridge between the edge of the ramp and the ground. Toes may be integral with the ramp or they may be loose items that are attached to the ramp only when needed. The known integral toes are hinged to the end of the ramp to fold under the ramp in the stowed position and are powered independently. This independent power source for the ramp toe is relatively expensive because the toe must be operated and phased with the operation of the ramp so that it does not become jammed. Also, the use of an independent ramp toe power source increases the chances that a portion of the power ramp system will be inoperative at any given time to prevent the effective utilization of the aircraft. Since the power device for the toes is usually hydraulic, and it is always possible that hydraulic pressure will not be available, latches or other means have been required between the ramp and the toe to assure that the toe is secured during flight.
It is desirable to use the ramp for the four main types of ramp loading/off-loading, that is, straight-in loading from cargo loaders, loading from various height truck beds, straight-in loading using fork lifts and drive-on or walk-off loading with the ramp fully down. Therefore, control means must be provided with the independently powered ramp toes to assure they remain in the desired position with respect to the ramp so that the desired loading configuration can be achieved.